Patent Application
20250034762
The invention relates to an industrial fabric, such as a fabric for a structured tissue paper machine, that has a combination of weft, or cross-machine direction, knuckles near the forming side surface of the industrial fabric and long warp, or machine-direction, knuckles at the forming side surface of the industrial fabric.
Soft, absorbent, disposable paper products, such as facial tissue, bath tissue, and paper towels, are a pervasive feature of everyday life. While there are numerous methods for manufacturing such products, in general terms, their manufacture begins with the formation of a cellulosic fibrous web in the forming section of a paper machine. The cellulosic fibrous web is formed by depositing a fibrous slurry, that is, an aqueous dispersion of cellulose fibers, onto a moving forming fabric in the forming section of the paper machine. A large amount of water is drained from the slurry through the forming fabric, leaving the cellulosic fibrous web on the surface of the forming fabric.
With through-air drying, a wet web can be dewatered and dried by non-compressive means. That is, there is vacuum dewatering and through drying. Through-air drying can be accomplished with a vacuum section that follows the forming section where the vacuum can have a vacuum box that pulls air through and removes water. After vacuuming, the web can then be transferred to a through-air drying (TAD) fabric that can carry the web through through-air dryers and a Yankee dryer.
One type of through-air drying is referred to as energy efficient technologically advanced drying, or “eTAD.” Similar to the above, the eTAD tissue production process consists of a paper machine with a forming section, press section, rush transfer/shaping section, and a drying section. However, there is no actual through-air drying involved. The forming section generally forms the sheet by depositing, or placing, a fiber and water mixture from a headbox to the space between a forming fabric and a press fabric. A web is formed on the forming fabric as the accompanying water is drained away through the forming fabric. The sheet formed from the web is then carried on a press fabric around a suction turning roll, where more water is removed from the sheet via vacuum, and is then presented to a shoe press nip for further mechanical dewatering. The backing roll, which is opposite the shoe press shoe, is a steam heated dryer cylinder and provides some thermal drying. With the eTAD process, the sheet is then transferred to the eTAD structuring fabric via a rush transfer, in which the surface speed of the backing roll may be up to 30% faster than the surface speed of the eTAD structuring fabric. In this transfer, the sheet is mechanically forced into the pockets of the eTAD structuring fabric, thereby generating bulk and softness in the sheet. The sheet is then transferred to a Yankee dryer, where it is dried with conductive heat transfer from the Yankee dryer, and convective heat transfer from the hot air hood that wraps around the Yankee dryer. Finally, the sheet is creped off the Yankee dryer with a crepe blade and is wound onto a reel.
While there are many methods for manufacturing bulk tissue products, the foregoing description should be understood to be an outline of the general steps shared by some of the methods. For example, the use of a Yankee dryer is not always required, as, in a given situation, foreshortening may not be desired, or other means, such as “wet creping,” may have already been taken to foreshorten the web.
It should be appreciated that TAD and eTAD fabrics may take the form of endless loops on the paper machine and function in the manner of conveyors. It should further be appreciated that paper manufacture is a continuous process that proceeds at considerable speeds. For example, a fibrous slurry is continuously deposited onto a forming fabric in the forming section of the paper machine, while a newly manufactured paper sheet is continuously wound onto rolls after it is dried.
Those ordinarily skilled in the art will appreciate that woven fabrics are created by weaving, and have a weave pattern that repeats in both the warp or machine direction (MD) and the weft or cross-machine direction (CD). Woven fabrics take many different forms. For example, they may be woven endless, or flat woven and subsequently rendered into endless form with a seam. In addition, any pattern marking imparted from a woven fabric to the formed paper product will impact the characteristics of the paper.
Papermaking fabrics are produced in a wide variety of styles designed to meet the requirements of the paper machines on which they are installed for the paper grades being manufactured. Generally, they comprise a base fabric woven from monofilament and may be single-layered or multi-layered. The yarns are typically extruded from any one of several synthetic polymeric resins, such as polyamide and polyester resins, used for this purpose by those of ordinary skill in the paper machine clothing arts.
The properties of absorbency, strength, softness, and aesthetic appearance are important for many products when used for their intended purpose, particularly when the products are facial or toilet tissue, paper towels, sanitary napkins, or diapers.
Bulk, tensile strength, absorbency, and softness are particularly important characteristics when producing sheets of tissue, napkin, and towel paper. To produce a paper product having these characteristics, a fabric will often be constructed so that the top surface exhibits topographical variations. These topographical variations are often measured as plane differences between strands in the surface of the fabric. For example, a plane difference is typically measured as the difference in height between a raised weft yarn strand and a raised warp yarn strand or as the difference in height between MD knuckles and CD knuckles at the fabric's surface. Often, the fabric surface will exhibit pockets, in which case plane differences may be measured as a pocket depth.
Both warp and weft yarns can be a primary factor responsible for the creation of the depth of the pocket, thus limiting caliper generation. An ideal TAD or eTAD fabric should provide for both MD and CD contact with the cellulosic fibers or web product, thus facilitating sheet transfer to the Yankee dryer, enhancing the TAD and eTAD fabric operation in the manufacturing process, and enhancing creping at the end of the process.
The present invention concerns a structuring fabric that is a woven fabric with a forming side surface and a machine side surface, a plurality of machine-direction (MD) yarns, and a plurality of cross-machine direction (CD) yarns arranged in first and second layers where the first layer is on the forming side surface and the second layer is on the machine side surface of the structuring fabric. At least a portion of the MD yarns are interwoven with the CD yarns such that the MD yarns pass over at least two of the CD yarns of the first layer, thereby forming a long warp knuckle at the forming side surface. Additionally, at least a portion of the CD yarns are interwoven with the MD yarns such that the CD yarns of the first layer pass over at least one of the MD yarns, thereby forming a weft knuckle near the forming side surface of the structuring fabric.
In certain embodiments, the MD yarns are arranged in two or more layers.
In other embodiments, the CD yarns are arranged in three or more layers.
In some embodiments, the MD yarns pass over at least three, at least five, at least seven, or at least 18 CD yarns of the first layer.
In certain embodiments, the CD yarns of the first layer pass over at least two, at least three, or at least 18 MD yarns.
In some embodiments, the fabric has one or more woven and/or nonwoven machine-side layers.
In yet other embodiments, the fabric has one or more pockets having a CD width of at least one MD yarn diameter. In certain other embodiments, the fabric has one or more pockets having a machine-direction (MD) length of at least one CD yarn diameter.
In some embodiments, the structuring fabric is an eTAD fabric.
In other embodiments, the forming side surface faces a fibrous web.
In certain other embodiments, the MD yarns and/or the CD yarns comprise a material selected from the group consisting of: carbon, polyamide, rayon, fiberglass, cotton, ceramic, aramid, polyester, metal, polyethylene, polypropylene, polycyclohexylenedimethylene terephthalate (PCT), cyclohexanedimethanol terephthalic acid (PCTA), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyetherketoneketone (PEKK), and polyethylene naphthalate (PEN).
In other embodiments, the MD yarns are between 0.20 mm-1.1 mm in diameter. In a particular embodiment, the MD yarns are 0.40 mm in diameter.
In some embodiments, the CD yarns are between 0.20 mm-1.1 mm in diameter. In a particular embodiment, the CD yarns are 0.30 mm in diameter.
In certain embodiments, the long warp knuckle at the forming side surface has a length between 2.0 mm and 5.0 mm. In yet other embodiments, the weft knuckle near the forming side surface has a length between 0.40 mm and 1.60 mm.
In certain embodiments, a plane difference between a top surface of the long warp knuckle and a top surface of the weft knuckle is between 0.05 mm and 1.0 mm. In some embodiments, a plane difference between a top surface of the long warp knuckle and a top surface of the weft knuckle is up to 0.50 mm. In yet some other embodiments, a plane difference between the top surface of the long warp knuckle and the top surface of the weft knuckle is between 0.25 mm and 0.50 mm.
In yet certain other embodiments, the fabric has one or more pockets having a MD length between 1.0 mm and 5.0 mm. In some embodiments, the structuring fabric comprises one or more pockets having a CD width between 0.3 mm and 2.0 mm.
In other embodiments, the fabric comprises a pocket depth where a plane difference between a top surface plane of the long warp knuckle or portion thereof defining a pocket length or width boundary and a top surface plane of one or more of a weft yarn, a warp yarn, a warp knuckle, or a weft knuckle defining a pocket bottom comprises a range of depths between 0.01 mm to 1.0 mm.
In certain embodiments, one or more of the MD and/or CD yarns is non-flat and/or non-smooth.
In some embodiments, the first layer of CD yarns comprises first and second CD yarns. In yet other embodiments, the first CD yarns differ from the second CD yarns in diameter, shape, and/or material.
In some embodiments, the structuring fabric is a woven fabric with a forming side surface and a machine side surface, a plurality of CD yarns, and a plurality of MD yarns arranged in first and second layers where the first layer is on the forming side surface and the second layer is on the machine side surface of the structuring fabric. At least a portion of the MD yarns are interwoven with the CD yarns such that the MD yarns of the first layer pass over at least two of the CD yarns, thereby forming a long warp knuckle at the forming side surface, and at least a portion of the CD yarns are interwoven with the MD yarns such that the CD yarns pass over at least one of the MD yarns of the first layer, thereby forming a weft knuckle near the forming side surface of the structuring fabric.
The terms “comprising” and “comprises” in this disclosure can mean “including” and “includes” or can have the meaning commonly given to the term “comprising” or “comprises” in U.S. Patent Law. Terms “consisting essentially of” or “consists essentially of” if used in the claims have the meaning ascribed to them in U.S. Patent Law. Other aspects of the invention are described in or are obvious from (and within the ambit of the invention) the following disclosure.
The term “yarn” or “yarns” in the following disclosure can refer to monofilaments, multifilament yarns, twisted yarns, textured yarns, coated yarns, bicomponent yarns, as well as yarns made from stretch broken fibers, of any materials known to those ordinarily skilled in the art. Yarns can be made of carbon, polyamide, rayon, fiberglass, cotton, ceramic, aramid, polyester, metal, polyethylene, polypropylene, and/or other materials that exhibit desired physical, thermal, chemical or other properties. Further examples of suitable materials include, e.g., polyethylene terephthalate (PET), polycyclohexylenedimethylene terephthalate (PCT), cyclohexanedimethanol terephthalic acid (PCTA), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyetherketoneketone (PEKK), polyethylene naphthalate (PEN), and yarns of a modified heat-, hydrolysis-, and/or contaminant-resistant polyester of the variety disclosed in, e.g., U.S. Pat. No. 5,169,499, incorporated herein by reference.
The terms “machine direction” (MD) and “cross-machine direction” (CD) as used in the following disclosure are used in accordance with their well-understood meaning in the art. That is, the MD of an industrial fabric, such as a belt, refers to the direction that the industrial fabric moves in a manufacturing process, such as a tissue, towel, or nonwovens making process, while CD refers to a direction perpendicular to the MD of the industrial fabric.
The term “forming side” or “sheet side” of an industrial fabric refers to the side of the industrial fabric that comes into contact with, or that faces, a sheet, paper, or web product being processed thereon. The forming side surface is the surface that faces a newly formed sheet or paper web when the industrial fabric is running on a paper machine.
The term “machine side” or “wear side” of an industrial fabric refers to the opposite side of the forming side of the fabric and is the side of the fabric that comes into contact with, or that faces, a component of a machine, such as a roller in a paper machine.
A “knuckle” as used herein generally refers to the length of a woven warp or weft yarn constituting a top or bottom surface of a fabric that respectively crosses over (floats over) one or more adjacent weft or warp yarns in the fabric. A knuckle may be at or below the plane of a forming side or machine side surface of a fabric. A “warp knuckle” or “MD knuckle” is one where the length of yarn constituting a top or bottom surface is a warp yarn that crosses over one or more weft yarns adjacent thereto. A “weft knuckle” or “CD knuckle” is one where the length of yarn constituting a top or bottom surface is a weft yarn that crosses over one or more warp yarns adjacent thereto.
Generally, a “short” knuckle is where the surface yarn crosses over (floats over) one other yarn adjacent thereto, and a “long” knuckle is where the surface yarn crosses over (floats over) two or more yarns adjacent thereto.
A plane difference in a woven fabric of the invention may be the difference between a top of a first strand and a top of a second strand, such as a top of a warp yarn and a top of a weft yarn, in the fabric. For example, in certain embodiments, a plane difference is the difference between a top of a highest warp knuckle at the forming side surface of a fabric to a top of a highest weft knuckle at the forming side surface of the fabric.
A “pocket” as used herein refers to the space between knuckles or portions thereof that are adjacent one another, e.g., adjacent warp and weft knuckles. For example, a pocket may be bounded in its length by first and second weft knuckles or portions thereof and in its width by first and second warp knuckles or portions thereof, where the warp and weft knuckles are adjacent to one another. In certain embodiments, a pocket may be bounded in its length by first and second warp knuckles or portions thereof and in its width by first and second weft knuckles or portions thereof, where the warp and weft knuckles are adjacent to one another. In some embodiments, a pocket is bounded in its length by first and second warp knuckles or portions thereof and in its width by third and fourth warp knuckles or portions thereof, where the warp knuckles are adjacent to one another. In certain embodiments, a pocket is bounded in its length by first and second weft knuckles or portions thereof and in its width by third and fourth weft knuckles or portions thereof, where the weft knuckles are adjacent to one another.
In some embodiments, a pocket may be formed with a length that is defined by the distance between two weft knuckles or portions thereof and a width that is defined by the distance between two warp knuckles or portions thereof. In certain embodiments, a pocket may be formed with a length that is defined by the distance between two warp knuckles or portions thereof and a width that is defined by the distance between two weft knuckles or portions thereof. In other embodiments, a pocket may be formed with a length that is defined by the distance between a first pair of weft knuckles or portions thereof and a width that is defined by the distance between a second pair of weft knuckles or portions thereof. In yet other embodiments, a pocket may be formed with a length that is defined by the distance between a first pair of warp knuckles or portions thereof and a width that is defined by the distance between a second pair of warp knuckles or portions thereof. In some embodiments, a pocket may be formed with a length defined by two weft or two warp knuckles or portions thereof and a width defined by one warp and one weft knuckle or portions thereof. In other embodiments, a pocket may be formed with a width defined by two weft or two warp knuckles or portions thereof and a length defined by one warp and one weft knuckle or portions thereof. In yet other embodiments, a pocket may be formed with a length defined by a warp and weft knuckle or portions thereof and a width defined by a warp and weft knuckle or portions thereof.
A repeating weave pattern in a fabric of the invention may create pockets that are defined by the repeating weave pattern.
Pocket depth is a distance from the top of a highest knuckle on the top, or forming side, surface of a fabric to a point lower or lowest within the pocket. For example, the depth of a pocket may be determined based on the distance from the plane of a top surface of a highest warp knuckle at the forming side surface of a fabric to a top surface of a lowest weft knuckle within the pocket. In some embodiments, the pocket depth may be determined based on the distance from the plane of a top surface of a warp knuckle defining a length or width boundary of the pocket to the plane of a top surface of a warp or weft yarn situated below and between the knuckles or portions thereof defining the pocket length and width. In certain embodiments, a pocket depth may comprise the distance from the plane of a first top surface of a yarn making up a knuckle defining a length or width boundary of the pocket, such as a warp knuckle, to the plane of a second top surface of the same yarn where the second top surface is situated below the first top surface and below and between the knuckles or portions thereof defining the pocket length and width boundary.
In yet other embodiments, the pocket depth is a range of depths based on the distance from the plane of a top surface of a knuckle defining a length or width boundary of the pocket to the various planes of top surfaces of warps and/or wefts and/or knuckles situated below and between the knuckles or portions thereof defining the pocket length and width boundary. In further embodiments, the pocket depth is an average depth derived from a measured range of depths. In yet other embodiments, the pocket depth is a nominal depth based on a targeted range of depths. In certain embodiments, the pocket depth is the maximum measured depth of the pocket.
As described herein, the instant invention relates to an industrial fabric, such as a structuring fabric, having CD knuckles near the forming side surface of the industrial fabric and at least one long MD knuckle at the forming side surface.
More particularly, at the forming side surface of a structuring fabric of the invention are one or more long warp knuckles. Weft knuckles are typically not at the highest plane of the forming side surface of the inventive fabric but rather near the highest plane of the forming side surface, e.g., below the top surface of the long warp knuckles. This height differential between the top of the warp and weft knuckles at the forming side surface results in a plane difference in the forming side surface between the top of the long warp knuckles and top of the weft knuckles.
The present invention provides an improved structuring fabric, such as an eTAD fabric, which exhibits favorable characteristics in embodiments of the invention for the formation of tissue paper and related products. For example, an eTAD fabric comprising a support shute design according to embodiments of the invention allows for a CD knuckle higher or lower in a forming side plane to allow for better sheet transfer at a creping roll or backing roll interface. Without a CD knuckle, it may be difficult to transfer the sheet of paper at this point in manufacture. In embodiments of the invention, the addition of the CD knuckle component higher in a forming side plane of the instant industrial fabric design allows for better sheet transfer from a backing roll to the industrial fabric. The support shute design in embodiments of the invention allows a CD knuckle to be in a high enough forming side plane to facilitate sheet transfer, but yet be below the highest fabric plane enough such that it does not affect sheet softness. For example, in certain embodiments, the instant invention relates to an eTAD fabric with long MD knuckles at the forming side surface together with an addition of a CD knuckle through the addition of a support shute (weft) to the fabric to help grab a sheet off a backing roll and thereby aid in the transfer of the sheet to the eTAD fabric.
Additionally, the inventive fabric design described herein, in certain embodiments, results in a reduction in pinholes in a sheet product produced on the fabric while at the same time maintaining good sheet product transfer to the fabric.
A structuring fabric of the invention may be woven in various weave patterns, such as complex or simple, and may be a single or multi-layered fabric. Examples of weave patterns that may be employed to create a structuring fabric of the invention include a plain, twill, basket, and/or a satin weave pattern. Structured fabrics of the invention may be woven from monofilament, plied monofilament, multifilament, and/or plied multifilament yarns. Yarns used in a fabric of the invention may be extruded from any one of several synthetic polymeric resins, such as polyamide and polyester resins, used for this purpose by those of ordinary skill in the machine clothing arts.
The structuring fabric may be made as a single layer support shute or any design or weave pattern where a forming side long MD knuckle can exist with a CD knuckle in a higher plane.
In some embodiments, a fabric of the invention comprises a double layer support shute design (that is, a double layer shute design that includes an extra shute (weft) in the forming side layer of the fabric so that there are at least twice as many wefts in the top (forming side) layer as in the bottom (machine side) layer of the fabric). In certain embodiments, a fabric of the invention may comprise a double layer of wefts having a weft ratio of 2:1, 3:1, or 3:2 between the number of wefts in the forming side layer versus the wear side (machine side) layer of the fabric. In a support shute fabric design, “support” shutes may be added in between holes that may be present between wefts over which a warp floats and which may be considered the “main” wefts. The support shute will typically have a different contour to the main weft in the fabric and may differ from the main weft in any number of ways, such as material, shape, and/or diameter, e.g., crimp. For example, in certain embodiments, the support shutes will have a smaller diameter than the main shutes in the same layer.
In some embodiments, a fabric of the invention comprises a double layer support shute design comprising two layers of CD yarns and one layer of MD yarns where the first layer of CD yarns is a forming side layer and comprises first and second CD yarns that differ from one another at least by diameter and where the second layer of CD yarns is a machine side layer that comprises yarns of the same or similar diameter as the first CD yarns of the first layer. In certain embodiments, increasing the diameter of the first CD yarn over the second CD yarn of the first layer results in increased warp knuckle length at the forming side surface of the fabric, resulting in increased softness of a paper product produced thereon, such as facial tissue, bath tissue, or paper towels. In certain other embodiments, increasing the diameter of the second CD yarn over the first CD yarn of the first layer results in increased forming side warp knuckle height and pocket depth, resulting in increased caliper of a fiber-based product produced thereon, e.g., a sheet caliper will be thicker, thus having more bulk.
In certain embodiments, the fabric comprises at least one layer of MD yarns and at least one layer of CD yarns. In other embodiments, the fabric may comprise one layer of MD yarns and two layers of CD yarns. In another embodiment, the fabric may comprise two layers of MD yarns and two layers of CD yarns. In yet another embodiment, the fabric may comprise three layers of MD yarns and two layers of CD yarns. In certain embodiments, a fabric of the invention may comprise two layers of MD yarns and one layer of CD yarns.
In one embodiment, the invention provides an eTAD fabric having both good sheet transfer from a backing roll to the eTAD fabric and from the eTAD fabric to a Yankee dryer.
In certain embodiments, a fabric of the invention may be used in a QRT® machine (Advantage™ QRT® technology machine by Valmet). The QRT® process is depicted in
Additionally, in certain embodiments, the yarns in an industrial fabric of the invention can be non-flat and/or non-smooth in conformation. In certain embodiments, some yarns may be non-flat and/or non-smooth while other yarns may be flat and/or smooth. Yarns that are not smooth and/or are not flat contribute, among other things, to a technical advantage in embodiments of the invention of better sheet transfer because of a plane difference between the MD knuckles and the CD knuckles at the forming side surface of a fabric of the invention. A non-flat and/or non-smooth yarn can aid in this transfer because such yarns create a fabric surface from which sheet product fibers can be more easily plied during sheet transfer. By contrast, a flat yarn would have greater surface area for a fibrous web to lay upon and therefore could be more difficult to transfer.
The MD yarns in a fabric of the invention may be any suitable dimension. For example, the MD yarns may have a diameter of, e.g., 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.80 mm, 0.90 mm, 1.00 mm, 1.10 mm, or values in between. In certain embodiments, the MD yarns in a fabric of the invention are uniform in diameter. In other embodiments, the MD yarns vary in diameter in a single fabric. For example, some MD yarns may be 0.30 mm and other MD yarns may be 0.40 mm in diameter in a single fabric.
The CD yarns in a fabric of the invention may be any suitable dimension. For example, the CD yarns may have a diameter of, e.g., 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.80 mm, 0.90 mm, 1.00 mm, 1.10 mm, or values in between. In some embodiments, the CD yarns of the invention are uniform in diameter. In other embodiments, the CD yarns vary in diameter in a single fabric. For example, some CD yarns may be 0.30 mm and other CD yarns may be 0.40 mm in diameter in a single fabric.
In some embodiments, all of the MD yarns and all of the CD yarns have the same diameter. In other embodiments, a portion of the MD yarns and a portion of the CD yarns have the same diameter while other portions of the MD yarns and the CD yarns in the same fabric have differing diameters. In yet other embodiments, all of the MD yarns vary in diameter from all of the CD yarns.
In some embodiments, the MD yarn count in a fabric of the invention may be, e.g., 20 yarns/cm, 30 yarns/cm, 40 yarns/cm, or values in between. In other embodiments, the MD knuckle length may be, e.g., 2.00 mm, 3.00 mm, 4.00 mm, 5.00 mm, or values in between.
In certain embodiments, the CD yarn count in a fabric of the invention may be 10 yarns/cm, 20 yarns/cm, 30 yarns/cm, 40 yarns/cm, 50 yarns/cm, or values in between. In some embodiments, the CD knuckle length may be, e.g., 0.40 mm, 0.50 mm, 0.60 mm, 0.70 mm, 0.80 mm, 0.90 mm, 1.00 mm, 1.10 mm, 1.20 mm, 1.30 mm, 1.40 mm, 1.50 mm, 1.60 mm, or values in between. In other embodiments, the CD knuckle length is 1 times to 4 times the diameter of an MD warp.
In some embodiments, the plane difference between a warp and weft knuckle (measured from the plane at the top of an MD knuckle to the plane at the top of a CD knuckle) may be, e.g., 0.05 mm, 0.10 mm, 0.15 mm, 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.50 mm, or values in between. In certain embodiments, the plane difference may be between 0.05 mm and 0.95 mm. In certain embodiments, the plane difference creates a pocket in the industrial fabric.
In contrast to determining a forming side surface plane difference in a fabric of the invention, pocket depth is not necessarily dependent on the placement of the highest CD knuckle at the forming side surface whereas a forming side surface plane difference is dependent on the placement of the highest CD knuckles in relation to the highest MD knuckles at the forming side surface of the fabric.
In some embodiments, one or more pockets in a structuring fabric of the invention have the same depth. In other embodiments, one or more pockets in the structuring fabric have differing depths. In yet other embodiments, some of the pockets in the structuring fabric have the same depth and other pockets in the same structuring fabric have differing depths.
In certain embodiments, a pocket length in an industrial fabric of the invention may be, e.g., 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0 mm, or values in between. In some embodiments, all pockets in the industrial fabric have the same length. In other embodiments, all pockets in the industrial fabric have differing lengths. And in yet other embodiments, some pockets in the industrial fabric have the same length while other pockets in the same fabric have differing lengths.
In some embodiments, a pocket width in an industrial fabric of the invention may be, e.g., 0.25 mm, 0.50 mm, 0.75 mm, 1.0 mm, 1.25 mm, 1.50 mm, 1.75 mm, 2.0 mm, or values in between. In some embodiments, all pockets in the industrial fabric have the same width. In other embodiments, all pockets in the industrial fabric have differing widths. And in yet other embodiments, some pockets in the industrial fabric have the same width while other pockets in the same fabric have differing widths.
In various embodiments, fiber from a fiber-based product produced on an industrial fabric of the invention may form in different depths of a pocket in the fabric. For example, in certain embodiments, the fibers will penetrate to within certain depths of a pocket but not to within the deepest depth of a pocket, e.g., fibers may penetrate beneath the plane of a long warp knuckle at the forming-side surface of the fabric and form within depths created by the planes at the tops of wefts and/or warps found within the pocket but not form within depths created by the planes at the tops of wefts and/or warps that are the lowest points in the pocket. Thus, in certain embodiments, fibers may form in a portion of a pocket in a fabric of the invention while other portions of the pocket, e.g., the very bottom depths of the pocket, do not contain fibers from the product produced thereon.
In some embodiments, the pockets in a single fabric may generally be uniform in measurement for one or more of the plane difference between MD and CD knuckles, pocket length, and/or pocket width. In other embodiments, one or more of the plane difference between MD and CD knuckles, pocket length, and/or pocket width may vary between pockets in the same fabric.
In certain embodiments, the structuring fabric is a multi-layered fabric. For example, one or more woven or nonwoven layers can be attached to the machine-side surface of a woven fabric having near-surface CD knuckles and long MD knuckles at the forming side surface. The one or more layers added to the machine-side surface can be chemically, thermally, or mechanically attached or bonded thereto. For example, the one or more layers added can be fused, laminated, glued, or woven to the machine side of the woven fabric that has long warp knuckles at the forming side surface and weft knuckles near the forming side surface. In some embodiments, the one or more layers added to the machine side surface can be extruded meshes, knitted structures, or other nonwoven structures such as films, foils, or spunbond layers.
Turning to the figures,
Table I below provides information concerning the yarn mesh, yarn count, air permeability, caliper, warp, shute, and support shute for the fabric of
The inventive fabric of
The diameter of the MD yarns of the fabric in
The yarn count of the MD yarns of the fabric in
The forming side pockets in the fabric of
When considering pocket depth, the bottom measurement for determining the pocket depth may include a range of measurements to allow for variation in the lowest planes associated with different yarns constituting a bottom of a pocket. For example, while the top plane of the pocket may be readily determined based on the top of an MD knuckle delineating, e.g., a width of the pocket, the bottom of the pocket may be determined based on a range of planes measured from the top of different warps, wefts, and/or knuckles situated below and between the knuckles delineating the length and width boundaries of the pocket.
Similar to
Modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the scope of the present invention. The claims to follow should be construed to cover such situations.
This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Patent Application Ser. No. 63/529,636, filed Jul. 28, 2023. The foregoing application is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63529636 | Jul 2023 | US |
